1. Field of the Invention
The invention relates in general to a semiconductor element and the display pixel and the display panel using the same, and more particularly to a light-emitting semiconductor element and the display pixel and the display panel using the same.
2. Description of the Related Art
Semiconductor technology is an impetus to electronic technologies and brings convenience to modern people in attending their everyday business.
In recent years, major breakthroughs in the organic light emitting diode (OLED) of the semiconductor industry have been made and attracted the focus of attention in the optical-electric industry.
Like an ordinary diode, an OLED emits a light by using the characteristics of the material. The electrons and the holes respectively emitted from the electron transport layer (ETL) and the hole transport layer (HTL) are combined in the emitting material layer (EML). During the combining process of the electrons and the holes, extra energy is released in the form of optical waves when the electrons are excited to return the basic state. Different materials produce different energy levels for the electrons and the holes, and so are the wavelengths and the colors of the generated light different.
Besides, the field-effect transistor (FET), a commonly used semiconductor element, is normally divided into two types: the junction field-effect transistor (JFET) and the metal-oxide-semiconductor field effect transistor (MOS).
The source, the drain and the channel of the JFET are semiconductors of the same type, but the gate is not of the same type. Therefore, there is a pn junction between the gate and the channel. During application, the junction receives an inverse bias-voltage, so that the width of the channel is controlled by the gate voltage.
The source, the drain and the channel of the MOS are semiconductors of the same type, but the gate and the channel are separated by an oxidation layer made of an insulating material. The voltage of the gate can control the width of the channel through electrical field in the channel disposed at the back of the oxidation layer.
The FET has two main applications: the signal amplifier and the electronic switch. The function of a signal amplifier is for generating a significant change in the current of the drain/source when the current of the drain/source or the voltage of the gate only has a slight change. The function of an electronic switch is for controlling the current of the drain/source to switch between two different states when the change in the current of the drain/source or the voltage of the gate is large enough.